Old English Sætern, a Roman god, also "most remote planet" (then known), from Latin Saturnus, originally a name of an Italic god of agriculture, possibly from Etruscan. Derivation from Latin serere (past participle satus) "to sow" is said to be folk-etymology.

An ancient Italic deity, popularly believed to have appeared in Italy in the reign of Janus, and to have instructed the people in agriculture, gardening, etc., thus elevating them from barbarism to social order and civilization. His reign was sung by the poets as "the golden age." [Century Dictionary]

Identified with Greek Kronos, father of Zeus. Also the alchemical name for lead (late 14c.). In Akkadian, the planet was kaiamanu, literally "constant, enduring," hence Hebrew kiyyun, Arabic and Persian kaiwan "Saturn." Related: Saturnian.